Dragon Age will be Bioware's own unique intellectual property. As such they will be able to write the story, characters, world, etc any way they want and change it in any way they want without having to first seek approval from another company. In addition, they will not have to pay royalties or licensing fees to said company for the rights to make a game using someone elses intellectual property.
From a game perspective, Dragon Age is shaping up to look pretty damn nice! You can find what little info has been released about it here:
http://www.bioware.com/games/dragon_age/Neverwinter Nights 2 is a continuation of the first game but is being developed by another studio. Bioware preferred instead to work on their own projects and passed the development torch to Obsidian. They are however still working with Obsidian in an advisory capacity only.